[hotrod]

If you are using a positive displacement blower, I would suggest you inject infront of the blower.

The blower being a positive displacement device, places a hard limit on the amount of air that can flow. Your boost and air flow is locked in by the overdrive ratio of the blower. If you cool the air charge post blower you will actually lower the boost pressure, but still have the same air flow due to charge air cooling.

If you inject after the blower the only gain you will get is a reduction in detonation limit by the cooling effect of the water on the manifold temps and the in cylinder effects.

If you inject ahead of the blower you will get higher air flow at the same overdrive ratio. By cooling the air ahead of the blower it will move more air with each revolution. The water mist will also tend to improve the internal sealing and thermal effeciency of a roots type blower, giving you less compressional heating for a given overdrive ratio.

It may be most useful to inject on both sides if you still get detonation with the pre-supercharger injection.

Larry